Lawmakers Are Unable to Agree on a Replacement for Embattled Prime Minister Nouri al-Maliki

BAGHDAD—Wrangling over a successor to Iraqi Prime Minister Nouri al-Maliki postponed a parliamentary session to elect a new government, but an outcry by politicians shortened the delay, lawmakers said.

The setbacks are stalling attempts to choose a leader to confront an Islamist offensive that has taken over large parts of the country and...